<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        a {
            text-decoration: none;
            font-size: 50px;
        }

        a:hover {
            color: orange;
            text-decoration: underline;
        }

        .bpx {
            width: 100px;
            height: 100px;
            background-color: skyblue;
        }

        .bpx:hover {
            width: 400px;
            height: 400px;
            background-color: green;
        }
    </style>
</head>

<body>
<a href="#">超链接</a>
<div class="bpx"></div>
</body>

</html>